Unknown things about the North Star

Due to the rotation of the Earth around the axis, stars change their position in the sky, grow and dive. However, the Earth's rotation is directed towards the North Star, making it seem never to move.

The North Star is 434 light-years away and 4,000 times brighter than the Sun. It is the 48th bright star in the sky and has an apparent magnitude of 2.02.

The apparent star level is the number that represents the brightness of a star when looking at reality from Earth. The smaller the star level, the brighter the star. The moon and Venus have negative star levels.

According to astronomers, the phenomenon of movement (the shaking of the Earth axis) causes the Earth axis to change direction every year. In about 500 years, it will no longer be towards the North Star.

The North Pole is a Cepheid-like pulsar. It shrinks and relaxes, changing brightness in a few days. The small point that we see with its naked eye is the synthetic light coming from a three-star system orbiting a common focus.

The first star Polaris A is a super giant star weighing 6 times the Sun. The second companion star Polaris Ab rotates around it with a distance of 2 billion km. The third star Polaris B is farther away.

The North Pole is actually a system of three stars orbiting a common focus.

Arctic stars in Vietnam are often mistaken for "Big Dipper".

Bac Dau is actually a constellation in ancient Eastern astronomy, consisting of 7 bright stars (Bac Dau), which are 7 star-shaped stars of the Big Bear constellation.

Because of its proximity to the North Star and easily recognizable, the ancients used this constellation to find the North Star (by extending the outer edge of the dipper by 5 times to the North Pole) to determine the North.